The present invention relates to a sheet conveyor mechanism for reproducing apparatus, and more particularly to such a conveyor mechanism in which an original to be copied is led past an exposure and scanning station by means of a transport device, is then further conveyed by at least two transport units arranged alongside a support surface for the original and is finally discharged at a delivery station, after it has circulated through the apparatus for the required number of times.
By means of the sheet conveyor mechanism described in German Offenlegungsschrift No. 2,026,063, documents to be copied are transported through the illumination and projection area of a reproducing machine. In the machine, a first transport unit designed as a document drum is disposed at the sheet processing station and is provided with means for securing the leading edge of a sheet to be transported and also with drive means which serve for moving the document past the sheet processing station as well as for stopping the drum at a predetermined point. A second transport unit composed of conveyor belts arranged at the lower right-hand part of the document drum moves the trailing edge of the sheet past the processing station, after the leading edge has been stopped. Due to the fact that the conveyor belts are arranged at the lower right-hand part of the document drum, the known conveyor mechanism is of considerable length so that the dimensions of the reproducing machine are increased and optimum utilization of space is prevented.
In German Auslegeschrift No. 1,902,112, a transport mechanism for reproducing apparatus has been disclosed in which an original to be copied is picked up from a supply stack and is conveyed to a support surface of an exposure station by conveyor belts; it is then further transported by conveyor belts and is finally placed on a delivery stack. In detail, a first switchable transport device takes up the individual original and conveys it to the support surface by means of a reversible conveyor belt mechanism set in motion by drive means which are also reversible. The drive means are controlled by a control circuit equipped with a distance measuring device which is actuatable by a switch responding to the individual original and which emits control signals as a function of the measuring values corresponding to the distance travelled. In this mechanism, no provision is made for stopping of the leading edge of the original. In order to allow reproduction of long originals the sheet conveyor mechanism must be elongated and it is, therefore, impossible to realize a compact design, desired in table copiers.